Some Queens students are outraged that the Alliance for Downtown New York took down posters the students put up last week marking sites in lower Manhattan where slavery-related events took place.

The alliance, which runs the financial area's Business Improvement District, removed the posters the same day, saying they were illegal.

"Who gave the Downtown Alliance the authority to touch our signs?" Jennifer Caroccio, a senior at the Law, Government and Community Service Magnet High School in Cambria Heights said at a meeting that she and other students held Wednesday to discuss the issue.

"I was amazed that the posters we worked so hard to create were taken down," said Aissata Camara, another student.

Senior Osele Clifford noted, "There are no memorials to the victims of slavery in New York. When the Downtown Alliance took down our posters, they were erasing slavery from history again."

Bruce Brodoff, an alliance spokesman, said yesterday, "We were just fulfilling our mission," part of which is to "keep downtown free of graffiti and illegal fliers."

Hoping to call attention to the city's role in the enslavement of Africans during the 17th and 18th centuries, the students stapled posters around lampposts along an "African-American Heritage Trail" they had mapped out in a class project. Information for the posters was based on an award-winning curriculum developed by Hofstra University professor Alan Singer.

Singer led about 50 students on a tour of the trail last Friday. Posters were placed at Wall Street, where slaves were auctioned; at Foley Square, the site of public hangings; and at nine other sites.

The students learned of the posters' removal after Steve Josefsberg, director of public safety for the alliance, sent an e-mail to Singer, saying Josefsberg was keeping the posters in his office.

"It is not legal to place these posters on traffic poles, light poles or pedestrian poles," Josefsberg wrote in the e-mail. He offered to help the students "get their message out."

Singer said yesterday, "I was disturbed when he told us they took them down. ... Their [the students'] reward for their achievement was to have their work removed."

Brodoff said Eric Deutsch, president of the alliance, is willing to discuss Singer's proposal to erect permanent markers.

"It seems like an interesting project to help them with in a more professional and organized manner," Brodoff said. "We're interested in promoting all the history that took place down here."